Night vision

About: Night vision is a research topic. Over the lifetime, 6004 publications have been published within this topic receiving 67372 citations.

Strain out a gnat and swallow a camel? - vision and driving in the Nordic countries.

Abstract: Purpose This study describes the present legislation for visual requirements for driving in the Nordic countries in relation to the European Driving License Directive. Methods Information about the formal legislation was gathered from each countries legal text. Further information about the implementation and common practices were achieved from national authorities in vision and driving. Results Even though the Nordic countries use the same framework of legislation, the implementation varies widely. Sweden and Norway have more specified visual field requirements than the others. On the other hand, no periodic testing of visual acuity (VA) is performed in Sweden as in all other Nordic countries. Physicians on Iceland are not obliged to report a person no longer fulfilling the visual requirements, as in other Nordic countries. In Denmark, Finland and Norway a person may apply for dispensation from the requirements by performing a practical driving test. In Sweden, a person applying for dispensation can undergo a traffic simulator test. Conclusion Because of the national legislation in the Nordic countries, a person with a visual impairment may be given different permissions depending on which country they live in. As the inhabitants in the Nordic countries frequently cross the regional borders, a harmonization of the legislation would be of value. More research in this field could provide future standards, combining the greatest autonomy with the highest possible safety.

Clinical Results and Some Problems of Multifocal Apodized Diffractive Intraocular Lens Implantation

Abstract: Purpose: To evaluate near and far visual outcomes, subjective visual symptoms, and patient satisfaction with AcrySof® ReSTOR® diffractive multifocal intraocular lenses (IOL), and to study the reasons for postoperative dissatisfaction. Methods: Twenty-three eyes of 19 patients received phacoemulsifications and implantation of AcrySof® ReSTOR® IOL. The main outcome measures, taken at postoperative 1 day, 1 week, 1 month, and 3 months, were uncorrected and corrected near and distant visual acuity, refractory errors, subjective visual symptoms (glare, halo, and night vision), and satisfaction. Results: At the 3-month postoperative visit, the mean uncorrected near and distant visual acuities were 0.59±0.24 (0.25±0.22 LogMAR unit) and 0.78±0.27 (0.13±0.10 LogMAR unit), respectively. In addition, patients’ satisfaction with uncorrected near vision, intermediate vision, far vision, and general visual performance were better than their satisfaction with night vision. Glare and halos were reported as severe by only 10.2% and 5.3% of patients, respectively. The seven eyes with poor patient satisfaction included eyes with a high incidence of preoperative ocular diseases or preoperative and postoperative high corneal astigmatisms of more than 1.0 diopter. Conclusions: The AcrySof® ReSTOR® IOL demonstrated good near and distant visual acuity with good patient satisfaction. Previous ocular disease, corneal astigmatism less than 1.0 diopter, and patient lifestyle should be considered to enhance patient satisfaction. J Korean Ophthalmol Soc 49(8):1235-1241, 2008

Imaging and detection of current conduction in dielectric films by emission microscopy

Abstract: Current conduction in dielectric films has been studied by Emission Microscopy. By combining optical microscopy with the latest night vision technology and the computer image processing techniques, we have been able to image the extremely faint light emission accompanying current conduction in a dielectric film on silicon substrate. We have found that current flows uniformly in an undamaged capacitor initially. The capacitor then breaks down after conducting a certain amount of charge and current flow becomes constricted into the failure location. To date, we have achieved a sensitivity of 10pA/µm2uniform current conduction through a 250A undamaged oxide. For a damaged oxide, our sensitivity is 50nA at 12V or 300nA at 5V, strongly depending on the degree of damage. The spatial resolution achieved is 0.5µm. With its unprecedented capability, Emission Microscopy can be readily used to study the physical mechanisms of dielectric conduction and pinpoint the location of gate dielectric failure.

MOSAD IR focal plane per pixel A/D development

Abstract: An on focal plane digital readout development suggested by the Army Night Vision & Electronics Sensors Directorate is proceeding under a combined program with the development of two color HCT detector arrays. The on focal plane A/D process is based on the Amain patented multiplexed oversample A/D, MOSAD, technology. In the first year of the program, prototype on focal plane analog to digital converters for both staring arrays and scanning arrays were built and demonstrated. The prototypes included a 2 loop double ended switched MOSAD and a 1 loop single ended MOSAD. Results from the original experimental prototypes showed conclusively that better than 14 bits could be achieved and that well capacity could be increased to support high background HCT needs approaching 109 electrons. In the second year, a 64 X 64 staring array for HCT LWIR detectors, 50 micron centers, was built based on these original prototype designs. The layout of the per pixel MOSAD A/D staring array used Orbit 1.2 micron CMOS process and achieved a pixel size of 40 microns with a well capacity of 1.9 X 108 electrons. Integration capacitors were built using Orbit's normal double poly capacitors with a standard buffered direct inject TIA detector interface configuration. Preliminary testing has been completed indicating complete functionality. Fermionics LWIR HCT detectors with cutoff at 9 microns have been built for attachment to the readout but indium bumping was not completed in time to report system level testing results. However, some noise tests have been performed using on array current mirrors. These tests indicate that better than 12 bits has been achieved, but lower noise current sources will be required for a more accurate measurement.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Homozygosity mapping reveals new nonsense mutation in the FAM161A gene causing autosomal recessive retinitis pigmentosa in a Palestinian family.

Abstract: Purpose: Retinitis pigmentosa (RP) is a heterogenous group of inherited retinal degenerations caused by mutations in at least 45 genes. Recently, the FAM161A gene was identified as the causative gene for RP28, an autosomal recessive form of RP. Methods: We performed a clinical and molecular genetic study of a consanguineous Palestinian family with two three siblings affected with retinitis pigmentosa. DNA samples were collected from the index patient, his father, his affected sister, and two non-affected brothers. DNA sample from the index was subjected to high resolution genome-wide SNP array. Assuming identity-by-descent in this consanguineous family we applied homozygosity mapping to identify disease causing genes. Results: The index patient reported night blindness since the age of 20 years, followed by moderate disease progression with decrease of peripheral vision, the development of photophobia and later on reduced central vision. At the age of 40 his visual acuity was counting fingers (CF) for both eyes, color discrimination was not possible and his visual fields were severely constricted. Funduscopic examination revealed a typical appearance of advanced RP with optic disc pallor, narrowed retinal vessels, bone-spicule like pigmentary changes in the mid-periphery and atrophic changes in the macula. His younger affected brother (37 years) was reported with overall milder symptoms, while the youngest sister (21 years) reported problems only with night vision. Applying high-density SNP arrays we identified several homozygous genomic regions one of which included the recently identified FAM161A gene mutated in RP28-linked autosomal recessive RP. Sequencing analysis revealed the presence of a novel homozygous nonsense mutation, c.1003C>T/p.R335X in the index patient and the affected sister. Conclusion: We identified an RP28-linked RP family in the Palestinian population caused by a novel nonsense mutation in FAM161A. RP in this family shows a typical disease onset with moderate to rapid progression into severe visual impairment including central vision in the index and overall milder symptoms in the younger brother and sister.